Duramycin (2622U90) is a 19 amino acid polycyclic peptide which has been shown to increase chloride permeability in cultured respiratory epithelial cells, in both human, and in patients with cystic fibrosis (CF). Therefore this compound is a rational candidate for CF therapy. The purpose of this study is to evaluate the safety and pharmacokinetics of aerosolized 2622U90 in healthy volunteers as well as patients with CF. Initial testing will begin with healthy normal volunteers. Three concentrations of 2622U90 will be evaluated in ascending order, and doses will escalate only after evaluating the safety and lack of adverse events for a 2 week period in all subjects. The primary endpoint in this study will be safety. Acute safety will be determined by monitoring pulmonary function by spirometry, gas exchange, continuous pulse oximetry, and other vital signals. Other more subtle pulmonary changes will be evaluated by chest radiographs, high resolution computed tomography of the chest, and measurement of static lung volumes and single breadth diffusion capacity for carbon. The characterization of the pharmacokinetics of 2622U90 after aerosol administration in humans will be performed by serially measuring plasma levels of the drug. PROPOSED COMMERCIAL APPLICATIONS: This is a pharmaceutical new product. Initially, it will be targeted to C.F. A possible "spin-off" benefit could be the use of duramycin for the management of bronchitis and asthma. The market size for these applications could reach $1 billion annually.